Certified Rhythm Analysis Technician (CRAT) Practice Exam

The description of an ECG rhythm as a "regular, P-P march" implies that there is a consistent pattern to the P waves, meaning they occur at regular intervals. This is characteristic of complete heart block (also known as third-degree AV block) where the atria and ventricles are depolarizing independently. In this condition, P waves can be seen regularly marching out as the atria contract, but they are not effectively leading to ventricular contraction, resulting in an overall disconnection between atrial and ventricular rhythms.

In complete heart block, while the P waves are regular, the QRS complexes can be of varying morphology and rates depending on the escape rhythm present in the ventricles. The "march" aspect indicates the P waves have a consistent timing, reinforcing that the atrial activity is unaffected by ventricular activity.

In contrast, the other options relate to varying degrees of AV block where the relationship between P waves and QRS complexes is disrupted, either through dropped beats or irregular timing, which does not align with the regularity indicated by "P-P march." For instance, Wenckebach (second-degree AV block type I) is characterized by progressive lengthening of the PR interval leading to a non-conducted P wave, and